Electric tuning frequency hopping filter with temperature compensation, frequency hopping communication system and communication equipment

Abstract

The invention relates to the technical field of communication equipment, and discloses an electric tuning frequency hopping filter with temperature compensation, a frequency hopping communication system and communication equipment, the filter comprises a digital logic control unit, a voltage amplification circuit, a temperature acquisition circuit, an electric tuning unit and a filter assembly; the temperature acquisition circuit acquires the temperature around the variable capacitance diode and outputs a temperature digital signal to the digital logic control unit; the digital logic control unit obtains the capacitance offset of the variable capacitance diode at the current temperature according to the temperature digital signal through internal table look-up, compensates the control voltage digital quantity of the variable capacitance diode corresponding to the pre-stored target frequency by combining with the user control code, and carries out voltage amplification processing on the control voltage digital quantity after temperature compensation. And the variable capacitance diode is driven and controlled to output a target capacitance value and is connected to the filter assembly to realize precise frequency hopping of the filter. The method is high in temperature compensation precision, high in environment adaptability and good in compatibility, and can be widely applied to various frequency hopping communication systems.

Description

Technical Field

[0001] This invention relates to the field of frequency hopping communication technology, specifically to an electrically tuned frequency hopping filter with temperature compensation, a frequency hopping communication system, and communication equipment. Background Technology

[0002] Frequency hopping filters are key components of frequency hopping communication systems. Their core function is to accurately track the carrier frequency hopping of the communication system in a very short time, allowing only the useful signal of the current frequency hopping channel to pass through, while effectively suppressing interference signals of other frequencies (including narrowband interference, co-channel interference, etc.). They are the core barrier to ensure that frequency hopping communication is "anti-interference, anti-interception, and highly reliable".

[0003] Existing frequency hopping filter technology block diagrams are as follows: Figure 2 As shown. From Figure 2 As can be seen, existing frequency hopping filters mainly consist of six parts: a control input port, a digital logic control unit, a voltage amplifier circuit, an electrically tunable element, a filter assembly, an RF input, and an output port. The mainstream technical solution is as follows: the user inputs the frequency hopping control code to the digital logic control unit through the control input port. The microcontroller inside the frequency hopping filter looks up a pre-stored table of "target frequency - tunable element control voltage digital quantity" based on the control code information, performs a D / A conversion on the digital quantity of the tunable element control voltage corresponding to the target frequency, and outputs an analog voltage signal in the range of 0-3.3V. After being amplified by the voltage amplifier circuit, the electrically tunable element (usually a varactor diode) outputs the corresponding capacitance value and is connected to the LC filter assembly unit to achieve switching between different communication frequencies.

[0004] In principle, a varactor diode, as a tuning element in an electrically tunable frequency-hopping filter, exhibits a non-linear change in capacitance when the applied reverse voltage changes: as the reverse voltage increases, the capacitance decreases; as the reverse voltage decreases, the capacitance increases. As a semiconductor device, the PN junction capacitance of a varactor diode is easily affected by temperature changes, causing capacitance shifts. When used in a frequency-hopping filter, the varactor diode performs normally at room temperature (25°C); however, when the operating environment deteriorates, its capacitance shifts due to temperature drift. Particularly when the temperature drops below -50°C or rises above 120°C, the capacitance shift can exceed 10%, causing the frequency-hopping filter to fail to hop accurately and affecting the stability and reliability of the equipment. Summary of the Invention

[0005] To address the problems and shortcomings of the existing technologies, this invention specifically proposes a temperature-compensated electrically tuned frequency hopping filter, a frequency hopping communication system, and communication equipment, which enhances the environmental adaptability of the frequency hopping filter and the stability and reliability of the equipment. To achieve the above-mentioned objectives, the technical solution of the present invention is as follows: Firstly, this invention discloses a temperature-compensated electrically tuned frequency-hopping filter. The temperature-compensated electrically tuned frequency-hopping filter includes a digital logic control unit, an electrically tuned unit, a filter assembly, and a temperature compensation control loop disposed between the digital logic control unit and the electrically tuned unit. The temperature compensation control loop includes a voltage amplification circuit and a temperature acquisition circuit. The input and output terminals of the voltage amplification circuit are respectively connected to the digital logic control unit and the electrically tuned unit. The temperature acquisition circuit is located near the varactor diode of the electronic tuning unit (located beside the varactor diode) to acquire the temperature around the varactor diode and convert the acquired temperature analog signal into a temperature digital signal for transmission to the digital logic control unit. The digital logic control unit obtains the capacitance offset of the varactor diode under the corresponding temperature condition based on the received temperature digital signal, and determines the digital quantity of the varactor diode control voltage corresponding to the target frequency after temperature compensation based on the capacitance offset. Finally, it converts the compensated digital quantity of the control voltage into the corresponding analog voltage signal and transmits it to the voltage amplifier circuit. The voltage amplifier circuit amplifies the received analog voltage signal and transmits it to the electrical tuning unit, driving the output of the temperature-compensated target capacitance value of the strain gauge diode to the filter assembly. The varactor diode is connected to the filter assembly, enabling the filter assembly to output the target frequency, thereby achieving precise switching of the target frequency.

[0006] Furthermore, the specific principle of temperature compensation for the digital logic control unit is as follows: The digital logic control unit (DLU) uses the temperature digital signal transmitted from the temperature acquisition circuit to look up its internally stored temperature-reverse voltage (VR)-capacitance offset relationship table to obtain the capacitance offset of the varactor diode at the corresponding temperature. Then, it calibrates the pre-stored digital value of the varactor diode control voltage corresponding to the target frequency based on the capacitance offset, thus obtaining the digital value of the varactor diode control voltage corresponding to the target frequency after temperature compensation. Specifically, the digital value of the varactor diode control voltage corresponding to the target frequency after temperature compensation is calculated using the following formula: Dt = D × (1 + △C); Where Dt is the digital value of the varactor diode control voltage corresponding to the target frequency after temperature compensation; D is the digital value of the varactor diode control voltage corresponding to the pre-stored target frequency; and ΔC is the capacitance offset of the varactor diode at the corresponding temperature. When the user sends a frequency hopping control code, the digital logic control unit outputs a digital quantity of the varactor diode control voltage corresponding to the target frequency after temperature compensation, based on the control code. After D / A conversion by the MCU's internal DAC peripheral, the corresponding voltage value is output. This voltage value is amplified by the voltage amplifier circuit and then input to the corresponding varactor diode, controlling the varactor diode to output the corresponding capacitance value to the filter component. In conjunction with the filter component, the target frequency is output, achieving precise frequency hopping.

[0007] Preferably, the temperature acquisition circuit includes a mixed-signal digital-analog temperature sensor chip U3, resistors R17 and R18, capacitors C32 and C33. The mixed-signal digital-analog temperature sensor chip U3 is an MTS4 chip, which integrates functions such as temperature acquisition and analog-to-digital conversion. The SCL and SDA pins of U3 are connected to the digital logic control unit via the T_SCL and T_SDA signal lines, respectively. Resistors R17 and R18 are respectively placed on the T_SCL and T_SDA signal lines. One end of capacitors C32 and C33 is connected in parallel to the VDD pin of the mixed-signal digital-analog temperature sensor chip U3, and the other end is connected to the GND pin.

[0008] Preferably, the digital logic control unit includes a main control MCU, a built-in memory and a high-speed SRAM, and the memory stores a temperature-reverse voltage VR-capacitance offset relationship table and a target frequency-varactor diode control voltage digital quantity relationship table.

[0009] It should be noted that the digital quantity of the varactor diode control voltage corresponding to the target frequency pre-stored inside the digital logic control unit is the digital quantity of the varactor diode control voltage under normal temperature conditions. When the ambient temperature changes and causes temperature drift in the varactor diode, it is necessary to calibrate and compensate the pre-stored digital quantity of the varactor diode control voltage to obtain the digital quantity of the varactor diode control voltage corresponding to the target frequency after temperature compensation. Then, based on the compensated digital quantity, the varactor diode is controlled to output the corresponding capacitance value, which, in conjunction with the filter component, outputs the target frequency.

[0010] It can be understood that, in order to quickly and easily obtain the digital value of the varactor diode control voltage corresponding to the target frequency at room temperature, a relationship table of the target frequency and the corresponding digital value of the varactor diode control voltage at room temperature can be pre-stored inside the digital control unit (forming a target frequency-varactor diode control voltage digital value relationship table). When a control code is received from an external user, the digital logic control unit directly looks up the digital value of the varactor diode control voltage at room temperature corresponding to the target frequency that matches the control code in the pre-stored relationship table.

[0011] Preferably, the digital logic control unit communicates with the outside world through the SPI interface and receives frequency hopping control codes sent by the user.

[0012] Preferably, the voltage amplification circuit includes an operational amplifier U2, resistors R2, R3, and R4, and capacitors C23 and C24. The positive input terminal of the differential operational amplifier U2 is connected to the output terminal of the digital logic control unit through resistor R2, and the inverting input terminal is grounded through resistor R3. The output terminal is connected to the input terminal of the electronic tuning unit and resistor R4, respectively. The other end of resistor R4 is connected between the inverting input terminal of the differential operational amplifier U2 and resistor R3. The positive power supply pin of the differential operational amplifier U2 is connected to an external power supply, and the negative power supply pin is grounded. After capacitors C23 and C24 are connected in parallel, one end is grounded, and the other end is connected between the positive power supply pin of the differential operational amplifier U2 and the external power supply.

[0013] Based on the above-mentioned electrically tuned frequency hopping filter with temperature compensation, the specific temperature compensation control method of the electrically tuned frequency hopping filter is as follows; S1: When the device is powered on and initialized, the temperature acquisition circuit starts up and acquires the ambient temperature around the varactor diode in the electronic tuning unit. Then, the acquired temperature analog signal is converted into a temperature digital signal and transmitted to the digital logic control unit. S2: After receiving the temperature digital signal, the digital logic control unit searches the internally stored temperature-reverse voltage VR-capacitance offset relationship table to obtain the capacitance offset ΔC of the varactor diode at the current temperature; S4: When the frequency hopping control code sent by the user through the control input port is received, the digital logic control unit outputs the calibrated and compensated digital value of the varactor diode control voltage Dt according to the control code, which is converted by the DAC peripheral and then output to the voltage amplifier circuit; wherein, the calibrated and compensated digital value of the varactor diode control voltage Dt is calculated as follows: After receiving the control code, the digital logic control unit first looks up the target frequency-varactor diode control voltage digital value D corresponding to the control code in the internally stored target frequency-varactor diode control voltage digital value relationship table. Then, based on the capacitance offset ΔC at the current temperature and the varactor diode control voltage digital value D at room temperature, the digital logic control unit performs temperature compensation on D using the following formula to obtain the calibrated and compensated varactor diode control voltage digital value Dt: Dt = D × (1 + △C); S4: The voltage value is amplified by the voltage amplifier circuit and then transmitted to the electric tuning unit to control the output target capacitance value of the corresponding strain gauge diode; S5: The electrically tuned unit is connected to the filter assembly, and the output target capacitance value of the capacitor diode is sent to the filter assembly. The filter assembly outputs the target frequency to achieve precise switching of the target frequency. Finally, the signal is transmitted through the radio frequency input / output port.

[0014] Secondly, the present invention also discloses a frequency hopping communication system, the communication system including the above-mentioned electrically tuned frequency hopping filter with temperature compensation.

[0015] Finally, the present invention also discloses a communication device comprising the above-described electrically tuned frequency hopping filter with temperature compensation.

[0016] The beneficial effects of this invention are: 1. The electrically tuned frequency hopping filter of the present invention has a temperature compensation function. By using the principle of real-time correction of the physical parameters of the tuning element through temperature feedback, the influence of ambient temperature on the filter is offset, ensuring that the electrically tuned frequency hopping filter can perform precise frequency switching under the user's control, thereby improving the environmental adaptability and reliability of the equipment and system. 2. The temperature compensation scheme of the present invention is applicable to various models of electrically tuned frequency hopping filter equipment. It is only necessary to modify the corresponding "temperature-capacitance offset" according to the temperature characteristic curve of the varactor diode selected for different frequency hopping filters. The frequency hopping information can be calibrated in real time through the digital logic control unit to compensate for the frequency offset caused by the temperature drift characteristics of the varactor diode under different ambient temperatures. It realizes the temperature compensation function of different frequency hopping filter models, with strong compatibility and simple debugging, which can significantly save design and production time costs.

[0017] 3. The temperature acquisition circuit of this invention is designed using a mixed-signal digital-analog temperature sensing chip. After the chip acquires the temperature, it undergoes small-signal amplification, analog-to-digital conversion, and digital calibration. Then, it communicates with the digital logic control unit (MCU) via an I2C bus, transmitting the converted digital temperature signal to the MCU to complete subsequent temperature compensation operations. These methods achieve high precision, high stability, and high integration in temperature acquisition, providing reliable data support for subsequent temperature compensation. Attached Figure Description

[0018] The foregoing and hereinafter detailed description of the invention becomes clearer when read in conjunction with the following drawings, in which: Figure 1 This is a schematic diagram of the electrically tuned frequency-hopping filter structure of the present invention. Figure 2 This is a schematic diagram of a current-technical frequency-hopping filter structure; Figure 3 This is a schematic diagram of the digital logic control unit of the present invention; Figure 4 This is a schematic diagram of the voltage amplifier circuit of the present invention; Figure 5 This is a schematic diagram of the temperature acquisition circuit of the present invention; Figure 6 This is a schematic diagram of the filter component of the present invention. Detailed Implementation

[0019] To enable those skilled in the art to better understand the technical solutions of this invention, several specific embodiments will be used to further illustrate the technical solutions for achieving the objectives of this invention. It should be noted that the technical solutions claimed by this invention include, but are not limited to, the following embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without inventive effort should fall within the scope of protection of this invention.

[0020] This embodiment discloses a temperature-compensated electrically tuned frequency-hopping filter, a frequency-hopping communication system, and communication equipment, such as... Figure 1 As shown, the electrically tuned frequency-hopping filter of the present invention mainly consists of a control input port, a digital logic control unit, a voltage amplifier circuit, a temperature acquisition circuit, and a filter assembly. The input terminal of the digital logic control unit is connected to the output terminal of the control input port and the output terminal of the temperature acquisition circuit. The output terminal of the digital logic control unit is connected to the input terminal of the voltage amplifier circuit, and the output terminal of the voltage amplifier circuit is connected to the input terminal of the electrically tuned unit. The input terminal of the temperature acquisition circuit is located near the varactor diode of the electrically tuned unit to acquire the temperature near the varactor diode. The filter assembly has an RF input port and an RF output port. The control input port, digital logic control unit, filter assembly, and electrically tuned unit of the present invention are inherent structures of frequency-modulated filters and can be referred to in known prior art; therefore, the present invention will not elaborate further. The digital logic control unit uses a domestically produced 32-bit microcontroller as the main control MCU, possessing abundant peripheral resources such as SPI, UART, ADC, and DAC. It has a built-in 512KB Flash and a maximum 68KB high-speed SRAM, with a maximum operating frequency of 200MHz, enabling high-speed communication, program storage, A / D conversion, D / A conversion, and fast frequency hopping functions for the frequency-hopping filter.

[0021] like Figures 3-5 As shown, the user provides 3.3V and 12V power to the frequency hopping filter through the control input port, which provides power input to the main control MCU, voltage amplifier circuit and temperature acquisition circuit respectively; by connecting the serial SPI interface SPI_CS, SPI_CSK and SPI_IN of the control input port to the main control MCU, the communication function between the user and the frequency hopping filter is realized.

[0022] The 0-3.3V analog voltage signal DAC_OUT output from pin 26 of the main control MCU is connected to... Figure 4The voltage amplifier circuit shown outputs a 0-15V analog voltage signal DAC_FD_OUT to the left of resistor R2 after voltage amplification. Figure 6 The common terminal of resistors R15 and R16 in the filter component unit circuit shown controls the capacitance values ​​of varactor diodes CT1 and CT2 at the corresponding voltage output. After being connected to the filter component, the corresponding frequency point is switched.

[0023] The temperature-reverse voltage VR-capacitance offset of the varactor diode is compiled into a table and stored in the memory of the main control MCU, forming a temperature-reverse voltage VR-capacitance offset relationship table. When temperature change information is collected, the corresponding offset information can be obtained simply by looking up the table, and temperature calibration and compensation can be performed. The varactor diode temperature-reverse voltage VR-capacitance offset relationship table used in this embodiment is shown in Table 1 below, where VR is the 0-15V analog voltage signal DAC_FD_OUT output after voltage amplification circuit. For example, referring to Table 1, when the temperature near the varactor diode is -20℃ and the reverse voltage VR is 5V, the corresponding capacitance offset of the varactor diode is -0.48%.

[0024] Table 1 Temperature-Reverse Voltage VR-Capacitance Offset

[0025] Figure 5 The temperature acquisition circuit shown connects to pins 42 and 43 of the main control MCU via I2C buses T_SCL and T_SDA, respectively, enabling communication between the main control MCU and the temperature acquisition circuit to obtain ambient temperature information around the varactor diode. The temperature acquisition circuit consists of a mixed-signal digital-analog temperature sensor chip U3, resistors R17 and R18, and capacitors C32 and C33. This temperature acquisition circuit should be placed as close as possible to the varactor diode. When the ambient temperature around the varactor diode varies within the range of -55℃ to 150℃, the bandgap voltage of the CMOS sensor inside the temperature sensor chip U3 changes. After small-signal amplification, analog-to-digital conversion, and digital calibration, the signal is transmitted to the main control MCU of the digital logic control unit.

[0026] Specifically, the SCL and SDA pins of the digital-analog mixed-signal temperature sensor chip U3 are connected to pins 42 and 43 of the main control MCU through the T_SCL and T_SDA signal lines, respectively. Resistors R17 and R18 are respectively set on the T_SCL and T_SDA signal lines. Capacitors C32 and C33 are connected in parallel, with one end connected to the VDD pin of the digital-analog mixed-signal temperature sensor chip U3 and the other end connected to the GND pin.

[0027] Figure 4This is a schematic diagram of a voltage amplifier circuit according to an embodiment of the present invention. The voltage amplifier circuit includes an operational amplifier U2, resistors R2, R3, and R4, and capacitors C23 and C24. The positive input terminal of the differential operational amplifier U2 is connected to pin 26 of the main control MCU through resistor R2, and the inverting input terminal is grounded through resistor R3. The output terminal is connected to the input terminal of the electronic tuning unit and resistor R4 respectively. The other end of resistor R4 is connected between the inverting input terminal of the differential operational amplifier U2 and resistor R3. The positive power supply pin of the differential operational amplifier U2 is connected to an external power supply (VCC_12V), and the negative power supply pin is grounded. After capacitors C23 and C24 are connected in parallel, one end is grounded, and the other end is connected between the positive power supply pin of the differential operational amplifier U2 and the external power supply.

[0028] The principle of temperature compensation for the frequency hopping filter in this invention is as follows: After the frequency hopping filter is powered on, the MCU completes system initialization (including the initialization of peripherals such as SPI and DAC). The temperature acquisition circuit starts working, converting the acquired temperature analog signal into a temperature digital signal and transmitting it to the main control MCU. The main control MCU judges the converted temperature digital signal and looks up the internally stored temperature-reverse voltage VR-capacitance offset relationship table to obtain the capacitance offset ΔC of the varactor diode temperature under the corresponding temperature condition. Simultaneously, the program scans the SPI data. When frequency hopping control code information is detected, it looks up the corresponding digital value D of the varactor diode control voltage at room temperature under the target frequency by referring to an internal table based on the control code information received from the SPI. Then, it calibrates and compensates the pre-stored digital value D of the varactor diode control voltage at room temperature based on the current capacitance offset ΔC. The digital value Dt of the varactor diode control voltage corresponding to the target frequency after temperature compensation can be calculated using the formula: Dt=D×(1+ΔC). The digital value Dt of the varactor diode control voltage corresponding to the target frequency after temperature compensation is converted into an analog voltage signal corresponding to the target frequency by activating the MCU's internal DAC peripheral. This analog voltage signal is amplified by the internal voltage amplifier circuit and drives the varactor diode to output the target capacitance after temperature compensation calibration. After being connected to the filter component, precise frequency switching can be achieved, increasing the environmental adaptability and reliability of the filter. The target frequency-varactor diode control voltage digital value relationship table (under room temperature (25℃) conditions) pre-stored in the internal memory of the digital logic control unit is shown in Table 2.

[0029] Table 2 Target Frequency - Varactor Diode Control Voltage (Digital Values) (at ambient temperature of 25℃)

[0030] Combining Tables 1 and 2, when the digital logic control unit receives a target frequency of 225MHz corresponding to the user control code, Table 2 shows that the digital value of the varactor diode control voltage at room temperature corresponding to this target frequency is 4095. If the temperature near the varactor diode is currently -20℃ and the reverse voltage VR is 5V, the capacitance offset of the varactor diode is -0.48%, then Dt = D × (1 + ΔC) = 4095 × (1 - 0.48%) = 4075. After the above temperature compensation, the digital value of the varactor diode control voltage corresponding to the target frequency is 4075. The digital logic control unit converts this compensated digital control voltage into a corresponding analog voltage signal and outputs it to the voltage amplifier circuit. After amplification, the voltage amplifier circuit drives the varactor diode to output the temperature-compensated target capacitance. After being connected to the filter component, the target frequency is output.

[0031] This invention adds a temperature acquisition circuit to the existing frequency hopping filter and optimizes the hardware configuration and control method of the digital logic control unit. By placing the temperature acquisition circuit near the varactor diode, the ambient temperature near the varactor diode is collected. The analog voltage signal, after signal amplification, is converted from analog to digital and transmitted to the digital logic control unit. The digital logic control unit, based on the received temperature information, looks up the capacitance offset of the varactor diode at the corresponding temperature in a pre-stored temperature-reverse voltage (VR)-capacitance offset table, and calibrates and compensates the pre-stored target frequency-varactor diode control voltage digital value relationship table based on this capacitance offset. When the user sends a frequency hopping control code through the filter's control input port, the digital logic control unit outputs the varactor diode control voltage digital value corresponding to the temperature-compensated target frequency according to the control code. After D / A conversion by the MCU's internal DAC peripheral, the corresponding voltage value is output. After voltage amplification, the varactor diode outputs the corresponding capacitance value, which is then connected to the LC filter component to achieve precise frequency hopping.

[0032] Based on the same inventive concept, this embodiment also discloses a frequency hopping communication system, which includes the above-mentioned electrically tuned frequency hopping filter with temperature compensation.

[0033] Furthermore, this embodiment also discloses a communication device, which includes the above-mentioned electrically tuned frequency hopping filter with temperature compensation.

[0034] The embodiments described above are merely preferred embodiments of the present invention and are not intended to hinder the present invention in any way. Any simple modifications or equivalent changes made to the above embodiments based on the technical essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. A temperature-compensated electrically tuned frequency-hopping filter, characterized in that, It includes a digital logic control unit, an electronically tuned unit, and a filter assembly. A temperature compensation control loop is provided between the digital logic control unit and the electronically tuned unit. This temperature compensation control loop includes a voltage amplification circuit and a temperature acquisition circuit. The input and output terminals of the voltage amplification circuit are respectively connected to the digital logic control unit and the electronically tuned unit. The temperature acquisition circuit is positioned close to the varactor diode in the electronic tuning unit to acquire the temperature around the varactor diode and transmit the temperature digital signal to the digital logic control unit. The digital logic control unit obtains the capacitance offset of the varactor diode under the corresponding temperature condition based on the received temperature digital signal, and determines the digital quantity of the varactor diode control voltage corresponding to the target frequency after temperature compensation based on the capacitance offset. Finally, it converts the compensated digital quantity of the control voltage into the corresponding analog voltage signal and transmits it to the voltage amplifier circuit. The voltage amplifier circuit amplifies the received analog voltage signal and outputs it to the corresponding varactor diode in the electronic tuning unit. The varactor diode outputs the temperature-compensated target capacitance value to the filter assembly, so that the filter assembly outputs the target frequency.

2. The electrically tuned frequency-hopping filter with temperature compensation according to claim 1, characterized in that, The digital logic control unit looks up the pre-stored temperature-reverse voltage VR-capacitance offset relationship table according to the received temperature digital signal, obtains the capacitance offset of the varactor diode at the corresponding temperature, and compensates the pre-stored digital amount of varactor diode control voltage corresponding to the target frequency according to the capacitance offset, so as to obtain the digital amount of varactor diode control voltage corresponding to the target frequency after temperature compensation. When the user sends a frequency hopping control code, the digital logic control unit outputs the digital quantity of the varactor diode control voltage corresponding to the target frequency after temperature compensation according to the control code. After D / A conversion by the MCU's internal DAC peripheral, the corresponding voltage value is output to the voltage amplifier circuit. After amplification, the varactor diode outputs the corresponding capacitance value to the filter component, so that the filter component outputs the target frequency.

3. The electrically tuned frequency-hopping filter with temperature compensation according to claim 2, characterized in that, The calculation method for the digital value of the varactor diode control voltage corresponding to the target frequency after temperature compensation is as follows: Dt = D × (1 + △C); Where Dt is the digital value of the varactor diode control voltage corresponding to the target frequency after temperature compensation; D is the digital value of the varactor diode control voltage corresponding to the pre-stored target frequency; and ΔC is the capacitance offset of the varactor diode at the corresponding temperature.

4. The electrically tuned frequency-hopping filter with temperature compensation according to claim 1, characterized in that, The temperature acquisition circuit includes a mixed-signal digital-analog temperature sensor chip U3, resistors R17 and R18, and capacitors C32 and C33. The SCL and SDA pins of the mixed-signal digital-analog temperature sensor chip U3 are connected to the digital logic control unit via the T_SCL and T_SDA signal lines, respectively. Resistors R17 and R18 are respectively placed on the T_SCL and T_SDA signal lines. One end of capacitors C32 and C33 is connected in parallel to the VDD pin of the mixed-signal digital-analog temperature sensor chip U3, and the other end is connected to the GND pin.

5. The electrically tuned frequency-hopping filter with temperature compensation according to claim 1, characterized in that, The model number of the digital-analog mixed signal temperature sensing chip U3 is MTS4.

6. The electrically tuned frequency-hopping filter with temperature compensation according to claim 1, characterized in that, The digital logic control unit includes a main control MCU, which has a built-in memory. The memory contains a table showing the relationship between temperature, reverse voltage (VR), and capacitance offset, and a table showing the relationship between target frequency and varactor diode control voltage.

7. The electrically tuned frequency-hopping filter with temperature compensation according to claim 1, characterized in that, The digital logic control unit communicates with the outside world through the SPI interface and receives frequency hopping control codes sent by the user.

8. The electrically tuned frequency-hopping filter with temperature compensation according to claim 1, characterized in that, The voltage amplification circuit includes an operational amplifier U2, resistors R2, R3, and R4, and capacitors C23 and C24. The positive input terminal of the differential operational amplifier U2 is connected to the output terminal of the digital logic control unit through resistor R2, and the inverting input terminal is grounded through resistor R3. The output terminal is connected to the input terminal of the electronic tuning unit and resistor R4. The other end of resistor R4 is connected between the inverting input terminal of the differential operational amplifier U2 and resistor R3. The positive power supply pin of the differential operational amplifier U2 is connected to an external power supply, and the negative power supply pin is grounded. After capacitors C23 and C24 are connected in parallel, one end is grounded, and the other end is connected between the positive power supply pin of the differential operational amplifier U2 and the external power supply.

9. A frequency-hopping communication system, characterized in that, The present invention includes an electrically tuned frequency hopping filter with temperature compensation as described in any one of claims 1-8.

10. A communication device, characterized in that, The present invention includes an electrically tuned frequency hopping filter with temperature compensation as described in any one of claims 1-8.

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